docs: def stopPolitely(self, disconnect=False):
          """Delete all active ROSpecs.  Return a Deferred that will be called
             when the DELETE_ROSPEC_RESPONSE comes back."""
          logger.info('stopping politely')
          if disconnect:
              logger.info('will disconnect when stopped')
              self.disconnecting = True
          self.sendMessage({
              'DELETE_ACCESSSPEC': {
                  'Ver': 1,
                  'Type': 41,
                  'ID': 0,
                  'AccessSpecID': 0  # all AccessSpecs
              }})
          self.setState(LLRPClient.STATE_SENT_DELETE_ACCESSSPEC)
  
          d = defer.Deferred()
          d.addCallback(self.stopAllROSpecs)
          d.addErrback(self.panic, 'DELETE_ACCESSSPEC failed')
  
          self._deferreds['DELETE_ACCESSSPEC_RESPONSE'].append(d)
          return d